gratuitous reposting of my own information:
it's cheap, and there's not much risk erring on the side of taking too much, although nolvadex has been demonstrated to have effects on vision similar to clomid's:
http://www.ncbi.nlm.nih.gov/entrez/...ve&db=PubMed&list_uids=10707134&dopt=Abstract
http://bjo.bmjjournals.com/cgi/content/full/88/1/125
it's well-known that formation of gynecomastia seems to depend on estrogen to testosterone ratios rather than on the absolute amount of estrogen:
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=1163504&dopt=Abstract
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2137877&dopt=Abstract
you can't get worse ratios than patients being treated with powerful anti-androgens. this closely correlates to post-cycle gyno conditions, where there is too much estrogen and not enough androgen. this study finds anastrozole(femara/arimidex style) doesn't work for prevention of post-cycle gyno -- well, duuh -- but furthermore, doses of 10mg of nolva are often sufficient, while up to 30mg may be necessary for extremely poor responders.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9426725&dopt=Abstract
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9426725&dopt=Abstract
http://www.ncbi.nlm.nih.gov/entrez/...ve&db=PubMed&list_uids=14759718&dopt=Abstract
for post-cycle HPTA use, the best study available on the subject suggests that even 5mg/day is plenty:
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=3931502&dopt=Abstract
"No statistically significant difference was found between the two subgroups of patients treated with either the lower (5 or 10 mg once daily) or higher dose of tamoxifen (10 mg twice daily) with respect to basal or LHRH stimulated gonadotropin and testosterone response or the E2/T ratio..."
as far as gyno, fat gain, or estrogenic water during cycles goes, nolvadex is poorly suited. nolvadex is a so-called SERM, meaning it has estrogenic activity at many types of tissue, which happens to include fat cells:
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9010344&dopt=Abstract
http://ajpregu.physiology.org/cgi/content/abstract/264/6/R1219
an aromatase inhibitor such as arimidex is a better choice, and is plenty effective against gyno in this situation:
http://jcem.endojournals.org/cgi/content/abstract/89/9/4428
given the superphysiological amount of testosterone and the presumable use of hcg, you'll still have enough estrogen washing around for its beneficial effects on lipids and bone content.
to recap; for post-cycle use, tamoxifen is the best drug we have available. 10-20mg/day of tamoxifen is sufficient for HPTA recovery and gynecomastia prevention, if not excessive. during cycles arimidex is a better choice, but if it's too expensive or not available, nolvadex will help prevent gyno at low doses, but can do nothing for fat gain. the risks of excess tamoxifen are small, including vision damage, but i hate using more drugs at higher doses than necessary.
but there's more bad news on the use of tamoxifen: it will reduce your circulating IGF-I levels. how much? 17% at 5-10mg/day, 47% at 20mg/day. this doesn't even take into account that it separately increases some binding protein levels.
http://www.ncbi.nlm.nih.gov/entrez/...ve&db=pubmed&dopt=Abstract&list_uids=11759825
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9758441
"Estrogens and the selective estrogen receptor modulator tamoxifen have been used previously to suppress circulating IGF-I levels in patients with acromegaly."
http://www.ncbi.nlm.nih.gov/entrez/...ve&db=pubmed&dopt=Abstract&list_uids=15223841
much of tamoxifen's action on breast cancer looks like it's mediated through this effect. interestingly, GH levels don't change, so this means that if you're shooting GH and running nolva, your circulating IGF-I levels will still be severely suppressed.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9364247
nolvadex also increases your levels of SHBG.
aromatase inhibitors are apparently themselves inhibited by nolvadex to some degree, but not vice versa. really weird pharmacokinetics and i couldn't explain why. some others have found nolvadex clearance increases -- i.e. lasts less in the body -- but this more recent study contradicts them. go figure.
http://clincancerres.aacrjournals.org/cgi/content/full/5/9/2338
http://clincancerres.aacrjournals.org/cgi/content/full/5/7/1642
you could use both at once but would have to up the dose of letrozole/arimidex to compensate for this effect.
also, the doses of femara we're taking are probably way too high. 0.5mg/day provides similar suppression as compared to 2.5mg -- virtually complete-- although researchers found additional suppression all the way up to 30mg/day. the curve really flattens out, though.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=8345034
should save some money...